About CH2

In 2004, the City of Melbourne was faced with an accommodation dilemma. Staff were housed in dated office buildings which although centrally located to the Town Hall, were nearing the end of their lifespan. Rather than relocate staff to alternative offices, Council embarked on an ambitious plan to construct a new office building, Council House 2 (CH2), that would meet its spatial requirements and lead the way in the development of an holistic green environment.

CH2 has been designed to not only conserve energy and water, but the quality of the internal environment of building has also been designed to improve the wellbeing of its occupants. CH2 demonstrates a new approach to workplace design, creating a model for others to learn from and follow.

CH2 emerged from a genuine commitment to explore how sustainable technologies could be integrated in every conceivable way, delivering tangible rewards to the property owner and its occupants alike.

In this section you can find more details of the objectives driving the design:

Conserving energy and water

Energy efficiency in CH2 is achieved through an integrated set of features focusing on heating, cooling and water reuse.

Elements that work together to achieve this goal include:

• Design based on ecology and climate
• Natural light
• Cooling system
• Heating system
• Vaulted concrete ceilings
• Western timber shutters
• Window treatment
• Water conservation
• Energy generation
• Waste management

• Design based on ecology and climate

  CH2 has been designed to reflect the planet’s ecology, which is an immensely complex system of inter-related components.

  The first focus of the design process for CH2 was to gain an understanding of Melbourne’s climate and weather patterns. An ecosystem responds to its environment, and its ability to adapt to take advantage of changing weather conditions contributes greatly to the success of the system.

  The design team found that responding to the site’s climactic conditions highlighted a range of opportunities for energy efficiency, and in doing so gave rise to some of CH2’s most innovative features.

  Melbourne is well known for its ‘four seasons in one day’. This variability could be viewed as a problem, but in the case of CH2, it was viewed as an opportunity to design the building around the concept of cold energy storage. The building therefore operates in two seasonal modes (winter and summer), as well as day mode and night mode.

  CH2’s many parts work together to heat, cool, power and water the building, creating a harmonious environment. More detail about how the building works as an ecosystem is contained within the below document:

  CH2 - How it works (2.5MB)

• Natural light

  CH2 targets and maximises the penetration of natural light within the building, reducing the requirement for artificial lighting.

  The building’s north and south facades are comprised of alternate vertical bands of glass and thick concrete walls containing supply-air ducts (on the south side) and exhaust-air shafts (on the north side). The shafts widen towards the upper levels in order to facilitate air supply and exhaust. Conversely, the windows are at their widest at street level, narrowing at the upper levels. This enables more light to be admitted to the lower levels of the building, where light access is restricted by surrounding buildings and there is less air demand at the end on the air ducts.

  CH2 takes advantage of natural light by:

• locating windows at the highest point of the curved concrete ceilings;
• an external ‘light shelf’ on the northern windows that, while protecting the windows from the direct rays of the sun, also bounces natural light into the building;
• moveable timber shutters that remain open to catch the morning sun, closing when the sun is in the western sky in the afternoon; and
• careful positioning and use of blinds to the northern windows. These windows are divided into upper and lower sections, each with its own blind. The upper blinds are only needed when the sun is low in the sky in winter. The lower blind is a partial blind (900mm high), to protect from the direct rays of the sun, while still letting in natural light.